This report concerning the immunization of adolescents (i.e., persons 11 to 21 years of age, as defined by the American Medical Association [AMA] and the American Academy of Pediatrics [AAP]) is a supplement to previous publications (i.e., MMWR 1994;43[No. RR-1]1-38; the AAP 1994 Red Book: Report of the Committee on Infectious Diseases; Summary of Policy Recommendations for Periodic Health Examination, August 1996 from the American Academy of Family Physicians; and AMA Guidelines for Adolescent Preventive Services: Recommendations and Rationale). This report presents a new strategy to improve the delivery of vaccination services to adolescents and to integrate recommendations for vaccination with other preventive services provided to adolescents. This new strategy emphasizes vaccination of adolescents 11 to 12 years of age by establishing a routine visit to their health care providers. Specifically, the purposes of this visit are to (1) vaccinate adolescents who have not been previously vaccinated with varicella virus vaccine, hepatitis B vaccine, or the second dose of the measles, mumps and rubella vaccine; (2) provide a booster dose of tetanus and diphtheria toxoids; (3) administer other vaccines that may be recommended for certain adolescents, and (4) provide other recommended preventive services. The recommendations for vaccination of adolescents are based on new or current information for each vaccine.